EMTRICITABINE AND TENOFOVIR DISOPROXIL FUMARATE (Page 2 of 10)
Emtricitabine and tenofovir disoproxil fumarate tablets for HIV-1 PrEP are contraindicated in individuals with unknown or positive HIV-1 status [see Warnings and Precautions (5.2)].
5 WARNINGS AND PRECAUTIONS
5.1 Severe Acute Exacerbation of Hepatitis B in Individuals with HBV Infection
All individuals should be tested for the presence of chronic hepatitis B virus (HBV) before or when initiating emtricitabine and tenofovir disoproxil fumarate tablets [see Dosage and Administration (2.1)].
Severe acute exacerbations of hepatitis B (e.g., liver decompensation and liver failure) have been reported in HBV-infected individuals who have discontinued emtricitabine and tenofovir disoproxil fumarate tablets. Individuals infected with HBV who discontinue emtricitabine and tenofovir disoproxil fumarate tablets should be closely monitored with both clinical and laboratory follow-up for at least several months after stopping treatment. If appropriate, anti-hepatitis B therapy may be warranted, especially in individuals with advanced liver disease or cirrhosis, since posttreatment exacerbation of hepatitis may lead to hepatic decompensation and liver failure. HBV-uninfected individuals should be offered vaccination.
5.2 Comprehensive Management to Reduce the Risk of Sexually Transmitted Infections, Including HIV-1 and Development of HIV-1 Resistance When Emtricitabine and Tenofovir Disoproxil Fumarate Tablets are Used for HIV-1 PrEP
Use emtricitabine and tenofovir disoproxil fumarate tablets for HIV-1 PrEP to reduce the risk of HIV-1 infection as part of a comprehensive prevention strategy that includes other prevention measures, including adherence to daily administration and safer sex practices, including condoms, to reduce the risk of sexually transmitted infections (STIs). The time from initiation of emtricitabine and tenofovir disoproxil fumarate tablets for HIV-1 PrEP to maximal protection against HIV-1 infection is unknown.
Risk of HIV-1 acquisition includes behavioral, biological, or epidemiologic factors including but not limited to condomless sex, past or current STIs, self-identified HIV risk, having sexual partners of unknown HIV-1 viremic status, or sexual activity in a high prevalence area or network.
Counsel individuals on the use of other prevention measures (e.g., consistent and correct condom use, knowledge of partner(s)’HIV-1 status, including viral suppression status, regular testing for STIs that can facilitate HIV-1 transmission. Inform uninfected individuals about and support their efforts in reducing sexual risk behavior.
Use emtricitabine and tenofovir disoproxil fumarate tablets to reduce the risk of acquiring HIV-1 only in individuals confirmed to be HIV-negative. HIV-1 resistance substitutions may emerge in individuals with undetected HIV-1 infection who are taking only emtricitabine and tenofovir disoproxil fumarate tablets, because emtricitabine and tenofovir disoproxil fumarate tablets alone does not constitute a complete regimen for HIV-1 treatment [see Microbiology (12.4)]; therefore, care should be taken to minimize the risk of initiating or continuing emtricitabine and tenofovir disoproxil fumarate tablets before confirming the individual is HIV-1 negative.
- Some HIV-1 tests, only detect anti-HIV antibodies and may not identify HIV-1 during the acute stage of infection. Prior to initiating emtricitabine and tenofovir disoproxil fumarate tablets for HIV-1 PrEP, ask seronegative individuals about recent (in past month) potential exposure events (e.g., condomless sex or condom breaking during sex with a partner of unknown HIV-1 status or unknown viremic status, or a recent STI), and evaluate for current or recent signs or symptoms consistent with acute HIV-1 infection (e.g., fever, fatigue, myalgia, skin rash).
- If recent (<1 month) exposures to HIV-1 are suspected or clinical symptoms consistent with acute HIV-1 infection are present, use a test approved or cleared by the FDA as an aid in the diagnosis of acute or primary HIV-1 infection.
While using emtricitabine and tenofovir disoproxil fumarate tablets for HIV-1 PrEP, HIV-1 testing should be repeated at least every 3 months, and upon diagnosis of any other STIs.
- If an HIV-1 test indicates possible HIV-1 infection, or if symptoms consistent with acute HIV-1 infection develop following a potential exposure event, convert the HIV-1 PrEP regimen to an HIV treatment regimen until negative infection status is confirmed using a test approved or cleared by the FDA as an aid in the diagnosis of acute or primary HIV-1 infection.
Counsel HIV-1 uninfected individuals to strictly adhere to the once daily emtricitabine and tenofovir disoproxil fumarate tablets dosing schedule. The effectiveness of emtricitabine and tenofovir disoproxil fumarate tablets in reducing the risk of acquiring HIV-1 is strongly correlated with adherence, as demonstrated by measurable drug levels in clinical trials of emtricitabine and tenofovir disoproxil fumarate tablets for HIV-1 PrEP Some individuals, such as adolescents, may benefit from more frequent visits and counseling to support adherence [see Use in Specific Populations (8.4), Microbiology (12.4), and Clinical Studies (14.3 and 14.4)].
5.3 New Onset or Worsening Renal Impairment
Emtricitabine and tenofovir are principally eliminated by the kidney. Renal impairment, including cases of acute renal failure and Fanconi syndrome (renal tubular injury with severe hypophosphatemia), has been reported with the use of TDF, a component of emtricitabine and tenofovir disoproxil fumarate tablets [see Adverse Reactions (6.2)].
Prior to initiation and during use of emtricitabine and tenofovir disoproxil fumarate tablets, on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all individuals. In individuals with chronic kidney disease, also assess serum phosphorus.
Emtricitabine and tenofovir disoproxil fumarate tablets should be avoided with concurrent or recent use of a nephrotoxic agent (e.g., high-dose or multiple non-steroidal anti-inflammatory drugs [NSAIDs]) [see Drug Interactions (7.1)]. Cases of acute renal failure after initiation of high-dose or multiple NSAIDs have been reported in HIV-infected patients with risk factors for renal dysfunction who appeared stable on TDF. Some patients required hospitalization and renal replacement therapy. Alternatives to NSAIDs should be considered, if needed, in individuals at risk for renal dysfunction.
Persistent or worsening bone pain, pain in extremities, fractures, and/or muscular pain or weakness may be manifestations of proximal renal tubulopathy and should prompt an evaluation of renal function in individuals at risk of renal dysfunction.
Treatment of HIV-1 Infection
Dosing interval adjustment of emtricitabine and tenofovir disoproxil fumarate tablets and close monitoring of renal function are recommended in all patients with estimated creatinine clearance 30 to 49 mL/min [see Dosage and Administration (2.6)]. No safety or efficacy data are available in patients with renal impairment who received emtricitabine and tenofovir disoproxil fumarate using these dosing guidelines, so the potential benefit of emtricitabine and tenofovir disoproxil fumarate tablets therapy should be assessed against the potential risk of renal toxicity. Emtricitabine and tenofovir disoproxil fumarate tablets are not recommended in patients with estimated creatinine clearance below 30 mL/min or patients requiring hemodialysis.
Emtricitabine and tenofovir disoproxil fumarate tablets for HIV-1 PrEP are not recommended in uninfected individuals with estimated creatinine clearance less than 60 mL/min. If a decrease in estimated creatinine clearance is observed while using emtricitabine and tenofovir disoproxil fumarate tablets for HIV-1 PrEP, evaluate potential causes and re-assess potential risks and benefits of continued use [see Dosage and Administration (2.6)].
5.4 Immune Reconstitution Syndrome
Immune reconstitution syndrome has been reported in HIV-1 infected patients treated with combination antiretroviral therapy, including emtricitabine and tenofovir disoproxil fumarate tablets. During the initial phase of combination antiretroviral treatment, HIV-1 infected patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia [PCP], or tuberculosis), which may necessitate further evaluation and treatment.
Autoimmune disorders (such as Graves’ disease, polymyositis, Guillain-Barr¡SR syndrome and autoimmune hepatitis) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable and can occur many months after initiation of treatment.
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